Review of Soft Linear Actuator and the Design of a Dielectric Elastomer Linear Actuator

Natural muscle provides excellent motilities for animals. As the basic unit of the muscle system, the skeletal muscle fibers function as a soft linear actuator. Inspired by the muscle fibers, researchers have developed various soft active devices with linear actuation. This paper reviews several soft linear actuators, such as the dielectric elastomer, thermal responsive hydrogels, pneumatic artificial muscle, and conducting polymers. The actuation mechanisms and performances of these soft linear actuators are summarized. Based on the dielectric elastomer, we propose a design of a hybrid system with linear actuation, driven by both the electric motor and dielectric elastomer cone. The electromechanical behaviors of the dielectric elastomer cone have been investigated in both experiment and finite element analysis. This work may guide the further design of soft actuators and robots.